Scaling hammer



May 21, 1929. E. w. STEVENS SCALING HAMMER Filed Oct. 9, 1926 IN VEN TOR.

50 WARD W. STEVENS ATTORNEY.

Patented May 21, 1929.

UNITED STATES PATENT OFFICE.

EDWARD w. STEVENS, or Dinner '1',v MICHIGAN, assrenon TO CHICAGO runuiu'rrc. TOOL comrm, on NEW YORK, N. Y., A conroaarron on NEW JERSEY. 1

SCALING HAMMER.

7 Application filed October 9, 1926-. Serial No. 140,446.

This invention relates in general to percussive tools, and in particular to tools of this type adapted and intended for use in removing the scale or incrusted coating which gathers in boilers, oil storage tanks, and the like. In cleaning oil storage tanks there is considerable danger due to the fact that inflamma ble and explosive gases are frequently present which may be set off by a spark produced by the percussive implement used to loosen and break up the scale. I

' Among the objects of the invention are to devise a percussive implement of the described type Which can be safely used in gas laden atmospheres, to surround the cutting or operation end of the tool with a non-inflammable atmosphere, to quench any sparks which may be produced and to prevent them from reaching any inflammable or explosive gas in the vicinity, and in general to improve prior devices ofthe described type and to in 1 crease the safety factor.

The invention rim of the tool from the surroundingatmosphere. A flexible cup shapedmemberof rubber or other suitable material'may be utilized for.

7 addition or alternatively any suitable spark quenchingjliquid may be fed, into the chamber adjacent the cuttingpart-s of the tool to eliminate all dangers i Such liquid mayassist in. the vcutting operation or in carrying away the cuttings and may make a tighter connection between the cupishapedmember and the surface operated upon. I

In order to illustrate the invention, the accompanying drawing shows avertical sec.- tional viewof one concrete embodiment.

The scaling-hammer disclosed inythe ac- I companying drawingis of the fluid-pressure valveless type and comprises acylinder 1 having a differential bore'in which reciprocates a piston 2 having ahead 2 and arreduced extension 2", the impacting endofithe latter bein serrated or otherwise'formed'as indi- 'cated at 2 .to break up the scale. Ahardened sleeve Sis press'edinto the front cylinder bore beconsidered as consisting in the'lnsulating of the-operatlve end i and; is provided with teeth to assist inbre'akmg up the scale. The rear end ofthe cylinder is sealed by a cap 4. "Motive fluid, such as compressed air, admitted through hollow handle 5, under control of a throttle valve (not shown) enters at port 6 and has access to the forward portion of the piston chant 7 her so that the pressure area 7 provided by the projection of head 2* is continuously subected to fluid pressure. This tends to drive piston 2 rearwardly until oneor more radial ports 2 in the piston extension 2* pass upwardly of and beyond the inwardly extending flange 1 of the cylinder, whereupon 1110- tive fluid passes through these ports into the rearwardly directed axial bore 2 of the piston so that pressure'accumulates against the large rear head of the pist-on overcoming the pressureagainst constant area 7 to drive thepiston forwardly to deliver its blow.v As thepiston'delivers its blow, radial ports 2 pass downwardly of and beyond flange'l and the pressure fluid at the'rear of thepiston chamber passes to exhaust between sleeve 3 and the forward extension 2* of the piston, whereupon the constant pressure againstarea 7 returnsthe piston, thus completing the cycle; f a

In orderto avoid danger from sparks resulting from the blows of the impact member which. might set off inflammable or explosive gases, suitable means are provided for insulating the portion of the work which is. under'the direct action ofthe tool. end the operative parts ofthetool are en-' terial adapted yieldinglytoengage' the plane or curved surfaces upon whichzthe tool op- TO' this 1 closed by aflexlble member 8 of suitable mathe lower end of cylinder l'andto'beclamped against a radially projecting. flange 1 by a nut 9-. As will be apparent from the previous descriptionthe exhaust moti ve fluid from the tool 1s .dlschargedabout the operative portions thereof and within the champressed against the work; Thissubstantially continues admission of a non-inflammable operating .fluid' together With-theolose en- 'gagement of member 8 with the work .eflfec ber provided by member 8 when. the tool is tive quenching of any spark that may be produced, the invention contemplates the ad-. mission of a suitable liquid to the chamber provided by member 8. To this end the jam nut 10 for motive fluid handle 5 has a hose connection at 11 communicating with a passage 1O in the nut which terminates in an annular groove 1O which registers with a similar annular groove 12 in the tool cylintle1-,wl1ence extends passages 13. and 14: to an annular groove15 in the front cylinder bore from which access to the interior of the sleeve 3 is provided by a series of slots 3 in the inner edge of sleeve 3. Any desired liquid, such as water, under the control of a suitable valve (not shown) may thus be directed into the chamber provided by member 8 and around the cutting portions of the tool. The liquid operatcs, not. only to quench all sparks, but also to assist in loosening the scale and in making a tight connection between member 8 and the surface being worked upon. It the admission of either air or liquid, or both, within memher 8 develops an excessive or undesirable pressure, one or more ports 16 of suitable size may be provided in member 8 to relieve the pressure.

VVhilea preferred form of the invention has been herein shown and described, it is to be understood that the invention is not limited to the specific details thereof, but covers all changes, modifications, and adaptations within the scope of the appended claims.

I claim as my invention: 7

1. The combination with percussive tool having operative parts including a striking element for working upon plane or curved surfaces of a flexible member inclosing said parts and arranged to engage such surfaces, the range of movement of said striking ele' ment being wholly within the confines of said tool and said member.

2. The combination with. a percussive tool having operative parts including a striking element for working upon plane or curved surfaces of a cup shaped member or molded rubber mclosmg said parts and arranged to engage such surl'aces,'the range of movement or said striking element being wholly W1th- 1n the confines otsaid tool and said memher, and means for discharging the exhaust motive fluid of said tool adjacent said parts.

and within said member. V

3. In combination, a fluid pressure percussive tool having impact'parts, a flexible mem ber secured to the outer'end of said tool to inclose the impact parts thereof and to engage the work, the range ofmovement of said parts being wholly within the confines 0i saidtool and saidmember, means for directing the exhaust motive fluid into said member, and means for feeding a spark quenching liquid into said member.

4. Incombination, a fluid pressure percus being wholly Within the coniines of said tool and said cup, means directing the exhaust motive fluid into said cup, and means for feeding water into said cup adjacent said parts.

,5. In combination, a fluid pressure pereussive tool, a cup-shaped member of flexible material clamped to said tool adjacent its end to enclose the impacting parts thereof, a rigid conduit for motive fluid to operate said tool, a jam nut for said conduit, and means including a passage in said nut for feeding liquid within said member.

6. In combination, a fluid pressure percussive tool, a cup-shaped member of flexible material. clamped to said tool adjacent its end to enclose the impacting parts thereof, a rigid conduit for motive fluid to operate said tool, a jam nut for said conduit, and means for conducting liquid into said member comprisinga passage in said nut termi natin in an annular groove in. the end. face thereoi and a pas'sagein. said tool arranged to communicate with said groove.

7. In combination, a fluid pressure percussive tool having a cylinder, apiston reciprocable within said cylinder,.and having an impact end, a sleeve having cutting teeth secured in the end of said cylinder and surrounding the impact end of said piston, a cup-shaped rubber member clai'nped to said cylinder andsurrounding said sleeve, means for supplying motive fluid to saidtool, and means for discharging liquid between said sleeve and said piston and within said member. i l

8. In combination, a fluid pressure percussive tool havinga cylinder, a piston reciprocable within said cylinder and having an impact end, a sleeve secured in the end of said cylinder and surrounding the impact end of said piston, a. cup-shaped rubber. member clampedtosaid, cylinder and surrounding said sleeve, a rigid conduitsecured to said cylinder to supply motive fluid thereto, a'jam nut for said conduit, a fluid connection to said nut, and passages including slots in said sleeve for discharging fluid between said sleeveand said piston and Within said member. v I V I 9. In combination, a fluid pressure percussive tool having a'cylinder, a piston reciprocable within said cylinder and having an impact end, a sleeve secured in the end of said cylinder and surrounding the impactend of said piston, a cup-shaped rubber member clamped to said cylinder and surrounding said sleeve,"a rigid conduitsecured to said cylinder to supply motive fluid thereto, 2. am

nut for' said conduit, afluid connection to said nut, passages including slots in said sleeve for discharging fluid between said sleeve and said piston and Within said member, and means for directing the exhaust motive fluid within said member.

10. In combination, a fluid pressure percussive tool havin a cylinder, a piston reciprocable within sald cylinder and having an impact end arranged directly to engage the work, a sleeve secured in the end of said cylinder and surrounding the impact end of said piston, a cup-shaped rubber member clamped to said cylinder and surrounding said sleeve, and means for discharging. the exhaust motive fluid between said sleeve and piston with in said member.

11. In combination, a fluid pressure percussive tool having a cylinder, a piston reciprocable within said cylinder and having an impact end provided with cutting teeth, a sleeve secured in the end of said cylinder and surrounding the impact end of said piston, a cup-shaped rubber member clamped to said cylinder and surrounding said sleeve, means for discharging the exhaust motive fluid between said sleeve and piston within said member, and means for discharging Water within said melnber.

12. In combination, a fluid pressurerpercussive tool having a cylinder, a piston reciprocable within said cylinder and having an impact end, a sleeve having cutting teeth se cured in the end of said cylinder and surrounding the impact end of said piston, a cup-shaped rubber member clamped to said cylinder andsurrounding said sleeve, means for discharging the exhaust motive fluid between said sleeve and piston within said member, means for discharging water within said member, and means for partly relieving the pressure within said member when in engagement with the work. i

13. In combination, a fluid pressure percussive tool, a flexible member secured to the the impact parts thereof, said member being arranged to inclose said parts and to engage the work, means for directing the exhaust motive fluid into said member, means for feeding a spark quenching liquid into said member, and means for partly relieving the pressure within said member when in engagement with the work.

14. In combination, a fluid pressure percussive tool, a flexible member secured to the outer end of said tool and extending beyond, the impact parts thereof, said member being arranged to inclose said parts and to engage the work, means for directing the exhaust motive fluid into said member, and means for feeding a spark quenching liquid into said member, said member having a port for relieving excessive pressure.

15. The combination with a percussivetool having operating 'parts for Working upon plane or curved surfaces,,of a flexible member inclosing said parts and arranged to engagesuch surfaces, the range of movement of said parts being within the'confines of said tool and said member,means fordischarging fluid adjacent said parts andwithin said member, and means for partly relieving excessive pres sure therein.

16. The combination with a percussive tool having operating parts for working upon plane or curved surfaces, of a flexible member inclosing said parts and arranged to engage such surfaces, the range of movement of said parts being within the confines of said tool and said member, and means for discharging fluid adjacent said parts and Within said member, said member having a port in the wall thereof to relieve excessive pressure.

Signed by me atDetroit, in the county of Wayne, and State of Michigan this 7 day of October- 1926.

' EDWARD W. STEVENS. 

